The present invention relates to a manually, longitudinally adjustable motor vehicle seat.
A motor vehicle seat is known from FR 2 865 974 B1. On each of its sides oriented in the longitudinal direction of the vehicle, this known seat has a rail pair, comprised of a lower rail and an upper rail, with the upper rail being longitudinally displaceably mounted in the lower rail, and being capable of being fixed in position, by locking means, in various longitudinal positions on the lower rail to provide an occupant a comfortable seating on the vehicle seat that is adapted to his or her anatomical characteristics. The lower rail is fixedly connected to the chassis of the vehicle, and the upper rail is connected to a component of the vehicle seat.
In addition to the above-described comfort-longitudinal adjustment of the seat, this known seat has a so-called easy-entry function, which is used in particular in 2-door vehicles to make getting into and out of rear seats of the vehicle easier for passengers. This function allows the vehicle seat, when the backrest is folded forward, to be shifted toward the front into an easy-entry-longitudinal adjustment range beyond its comfort-longitudinal adjustment range.
To be able to lock the upper rails in position on the lower rails, in the comfort-longitudinal adjustment range the lower rails are provided on both sides with a plurality of spaced-apart arresting notches that are open toward the bottom. Depending upon the adjusted longitudinal position of the seat, in the locking position latching teeth of a locking plate that is part of the locking mechanism engage in one of these arresting notches, whereby the locking plate is pre-tensioned in the locking position and can be pressed downwardly by means secured to the upper rail against the pre-tensioning for the release, so that the latching teeth exit downwardly out of the arresting notches. Such a locking mechanism is known in the state of the art, and is also described in principle in FR 2 865 974 E1.
Motor vehicle seats of the type described have the requirement that in the easy-entry-longitudinal adjustment range, the upper rails remain released from the lower rails, even if in the easy-entry-longitudinal adjustment range the backrest is folded back into its position of use. This problem is resolved by the prior art in that the lower rails have no arresting notches in the easy-entry-longitudinal adjustment range. The drawback of this is that for motor vehicles seats having different lengths of comfort-longitudinal adjustment ranges, correspondingly different lower rails have be manufactured.
If the easy-entry-longitudinal adjustment ranges are very long, it is possible for the walking plate to come entirely out of the lower rails. If in this case the vehicle seat is in the easy-entry-longitudinal adjustment range, and the backrest is folded back into its position of use, the locking plate assumes its locking position externally of the lower rail, with the consequence that when the vehicle seat is pushed back into the comfort-longitudinal adjustment range, the locking plate runs against the end face of the lower rail, which can lead to failure or destruction of the locking mechanism.
A further motor vehicle seat of the aforementioned general type is known from DE 103 39 056 A1. This vehicle seat has a first lever, which is pivotably hinged to the upper rail and is connected with the backrest via a Bowden cable. When the backrest is folded forward into the easy-entry-position, the first lever is pivoted by the Bowden cable into a release position, in which locking means between the lower rail and the upper rail are released. The vehicle seat has a second cable, which is also pivotably mounted on the upper rail. This second lever is pre-tensioned on the first lever, and has a first lever arm and a second lever arm. When the first lever is in the release position, the first lever arm of the second lever engages behind a recess of the first lever and, due to the pre-tension that is acting upon the second lever, holds the first lever in its release position. In this way, the locking means between the upper rail and the lower rail remain released in the entire easy-entry-longitudinal adjustment range. When the vehicle seat is shifted back out of the easy-entry-longitudinal adjustment range into the comfort-longitudinal adjustment range, the second lever arm of the second lever butts against an abutment that is secured to the lower rail, as a result of which the second lever pivots against the pre-tension and again releases the first lever, so that the locking is again established between upper rail and lower rail. The drawback of this known vehicle seat is that the means for preserving the release in the easy-entry-longitudinal adjustment range have a relatively complicated construction.
It is an object of the present invention to provide a motor vehicle seat of the aforementioned general type with which the lower rail can be provided with arresting notches over its entire length, and with which when the easy-entry-longitudinal adjustment ranges are particularly great, damage to the locking means when the motor vehicle seat is pushed back out of its easy-entry-longitudinal adjustment range into its comfort-longitudinal adjustment range is avoided with straightforward means.